Angular 4 Restful Post响应，带有“ SyntaxError：JSON.parse处的JSON输入意外结束”

Question

Below I have the following Angular segment which appears to attempting to handle the response as JSON even though 'httpOptionsText' is a constant defined as:

const httpOptionsText = {
    headers: new HttpHeaders({
    'Content-Type': 'text/plain'
    })
}; 

addOrders(order, rootUri): Promise<DetailOrderbean[]> {
let body = JSON.stringify(order);
const url = rootUri + 'api/data/addDetailOrder?order=' + body;

return this.http.post<DetailOrderbean>(url, body, httpOptionsText)
    .toPromise()
    .then(res => {
           console.log(res);
    })
    .catch(this.handleError);
}

Additionally, the java is specifying

        response.setContentType( "text/plain");
        response.setHeader("Access-Control-Allow-Origin", 
        "http://localhost:4200");
        response.setHeader("Access-Control-Allow-Credentials","true");

The status is 200, so I just want to consume the error. However, in the event of an actual error I need the handleError as it exits:

private handleError(error: any): Promise<any> {
    console.error('An error occurred', error);
    return Promise.reject(error.message || error);
}

Answer 1

I cast a structure inappropriately to the post () which forced the json conversion. This could also be seen by the compilar error:

Types of property 'responseType' are incompatible. Type '"text"' is not assignable to type '"json"'.

This should have told me that something was up with my return response type.